Two common approaches for Agile adoption have been frameworks (eg Scrum, SAFe) or improvement via kaizen (eg Kanban Method). The advantage of the first is that it provides a solid starting point. But this works against us as well since the preset framework may not fit the team or organization attempting to use it. Also, frameworks tend to work on proxies of the work to be done. For example, having cross-functional team working in a time-boxed results in lowering delays and handoffs. Good things. But by focusing on the time-box instead of the delays time-boxing reduces, those using Scrum don’t learn as much about reducing delays as they might otherwise.
The Kanban Method has the advantage of focusing directly on the work. By not having an immutable aspects, however, it often does not provide enough structure.
What’s needed is an explicit approach which directly focuses on the work but is contextualized to the organization using it. I suggest laying out the ideal workflow (value stream network) for the organization as a start. This can be used to identify current impediments to that workflow as well as action items to remove them impediments. A customized roadmap can now be created by seeing the optimal sequence of implementing these improvements.